Abstract

Partitioning in aqueous two-phase systems (ATPS) is mainly a process where the exposed groups of molecules come into contact with the phase components, and is therefore surface-dependent (1). Among the main protein properties, hydrophobicity and charge appear to be the most important parameters in ATPS. The interactions between the properties of the surface of the proteins and the properties of the systems determine the partitioning behavior. A protein interacts with the surrounding molecules within a phase via various bonds such as hydrogen, ionic, and hydrophobic interactions, together with other weak forces. The net effect of these interactions is likely to be different in the two phases and the protein will partition preferentially into one phase, in which the energy is most favorable (2).